Which of the following is a non-reducing carbohydrate?
(d) Ribose 5-phosphate
Sucrose is a disaccharide of glucose 8 fructose.It is a non-reducing sugar as it do not contain any free anomeric carbon atom. Maltose is a disaccharide of 2 glucose units. Its first glucose residue cannot undergo oxidation whereas second residue can undergo oxidation because it has a reactive free anomeric carbon atom. Hence, it is a reducing sugar.
Lactose and ribose-5-phosphate are also reducing in nature due to the presence of a free ketonic or aldehyde group